Header Page of 161 MINISTRY OF EDUCATION AND TRAINING MINISTRY OF HEALTH HA NOI MEDICAL UNIVERSITY LE LONG NGHIA SURGICAL RESEARCH APPLICATIONS USING SUBEPITHELIAL CONNECTIVE TISSUE GRAFT FOR RECOVERING EXPOSED TOOTH ROOT SURFACE Specialty: Dentistry Code: 62.72.06.01 PHD THESIS SUMMARY OF MEDICINE HANOI 2013 Footer Page of 161 Header Page of 161 The work was completed in HA NOI MEDICAL UNIVERSITY The scientific guides: Prof.PhD Mai Đinh Hưng PhD Nguyen Manh Ha Reviewer 1: Prof.PhD Đỗ Quang Trung Reviewer 2: Prof.PhD Đỗ Duy Tính Reviewer 3: Prof.PhD Trương Uyên Thái The thesis will be defended at the University level Council at Hanoi Medical University At time: hour, day month year 2013 The thesis can be found at: National Library of Vietnam Library of Hanoi Medical University Footer Page of 161 Header Page of 161 INTRODUCTION The apical migration of the gingival margin is called gingival recession Gingival recession may occur on proper or misaligned teeth, crown or bridge teeth, dental implant teeth Gingival recession may lead to many problems and functional aesthetics The percentage of gingival recession is relatively high in the World and Vietnam Surgery treatment for gingival receded tooth patients has not been done much in Vietnam’s hospitals and dental offices For that reasons, we performed the study named “ Surgical research application using subepithelial connective tissue graft for recovering exposed tooth root surface” This method combines the advantages of the pedicle flap methods and the autogenous free gingival graft The goals of the study are: Comment the clinical features of the gum receding cases Evaluate the results of surgery about its safety, recovering the denuded roots and changes of the gingival index URGENCY OF THE THESIS: The gingival recession is common in people, however the treatment is little done at Vietnam Hospitals and Dental offices The research on the treatment of Vietnam was less done Our research focuses on the connective tissue grafting, this method is more internationally recognized as highly effective for covering the tooth root surface PRACTICAL IMPLICATIONS AND CONTRIBUTIONS OF THE THESIS: The results of the treatment showed that more than 71% of the tooth root surface was recovered This surgery is safe and effective at covering the Footer Page of 161 Header Page of 161 rooth surface The aesthetic and functional results were maintained stabiy in the follow-up time This surgery is highly applicable and can be implemented in all Dental offices and Hospitals THESIS STRUCTURE: Introduction pages, Overview 29 pages, Subjects and Methods 17 pages, Results 34 pages, Discussion 23 Pages, Conclusion pages There are 93 references Chapter 1: OVERVIEW DEFINITION OF GINGIVAL RECESSION: Gingival recession is a process in which the gingival margin receded to the apex of the root (according to Glickman [15]) CLASSIFICATION OF GINGIVAL RECESSION:  Miller’s classification [16]: Class 1: The recession does not extend to the muco-gingival junction and the periodontal tissue between teeth is not destroyed Prognosis: the whole denuded tooth root surface may be recovered by surgery Class 2: The recession extends to or beyond the muco-gingival junction and the periodontal tissue between teeth is not destroyed Prognosis: the whole denuded tooth root surface may be recovered by surgery Class 3: The recession extends to or beyond the muco-gingival junction and the interdental periodontal tissue is injured Prognosis: the denuded tooth root surface may be recovered partly by flap surgery Class 4: class plus loosen teeth resulting from periodontitis Prognosis: Surgery treatment for covering denuded tooth root surface cannot be successful If these teeth are indicated to be conserved, surgery for augmenting attached gingiva Footer Page of 161 Header Page of 161 Picture 1.10: Miller’s classification [16] CAUSES AND FACILATING FACTORS OF GINGIVAL RECESSION: There are many causes of gingival recession such as physiological, pathological, traumatic or a combination of these causes Moawia M.Kassab et al [17] aggregated some studies and concluded that there are many causes leading gingival recession  Pathological causes: Periodontitis, deep periodontal pockets often lead to gingival recession  Traumatic causes: Incorrect tooth brushing technique at a long time makes gum worn Khocht A et al reported that there was a relation between hard tooth brushing habit and gingival recession [18] Occlusal trauma is a favorable factor that makes gingival recession aggravate because it can lead to more epithelial proliferation and local inflammation  Physiological causes: Footer Page of 161 Header Page of 161 Physiological gingival recession increases with age, gingival recession rate increase from 8% at child age to 100% at age of 50 (according to Glickman [15]) After a study in Germany 1991 on 11401 people, KleberBM concluded that 10,4% of persons had gingival recession at age of 16 to19; 24,8% of persons had gingival recession at age of 20 to 24; 46,8% of persons had gingival recession at age of 35 to 44 [19]  Physiological and anatomical favorable factors: The gingival recession is affected by the position of the teeth in the arch, the angle of the tooth root in the jaw For example: the canine erupts toward the labial side, the outer bone layer is thin and the gingiva is thin too, therefore it is easy for the gingival margin to recede CONSEQUENCES OF GINGIVAL RECESSION: - The denuded tooth root surface is easy to be decayed - Tooth root cement surface is worn by hard brushing habit leading to dentin hypersensitivity - It is easy for food debris, plaque and bacteria to adhere to tooth root surface at interdental space - Compromise esthetic if gingiva recession occurs on front teeth STUDY ABOUT GINGIVAL RECESSION IN VIETNAM AND ON THE WORLD: Along with the development of cosmetic dentistry, gingival recession has been more concerned In 2000, Arowojulu reported the gingival recession rate of a group of Nigeria people: ages 16-25 : 22%; ages 56-65 : 58% [3] In 2002, Hoanguan and colleagues reported the results of studies on the gingival recession of adult groups in Thailand: : ages 51 - 59 : 49,6%, ages Footer Page of 161 Header Page of 161 70 - 92 : 72%, gingival recession had been more prevailed in men than women [4] In 2004, Sucin C et al examined 1460 people in the urban area of Brazil and obtained results: More than half (51.6%) and 22.0% of the individuals and 17.0% and 5.8% of teeth per individual showed gingival recession > or = mm and > or = mm, respectively [1] In 2012, Minaya-Sanchez et al reported the gingival recession ratio in pure Mexican men: The mean number of sites with gingival recession per subject was 4.73; the prevalence was 87.6% In 1999, Long Le Nghia reported a research on 178 patients at National Odonto-Stomatology hospital about gingival recession rate: ages 18-25: 72,16%; ages 35-44 : 98,77% [5] GINGIVAL RECESSION TREATMENT: Gingival recession is a periodontal tissue defect and should only be treated by surgery Surgical treatment has divided into three groups: *Pedicle flap surgery: -Laterally sliding flap -Oblique rotated flap -Double papilla sliding flap -Cervically repositioned flap - Semilunar flap *Autogenous mucosal tissue graft: -Autogenous free gingival graft -Subepithelial connective tissue graft *Using membrane combined with pedicle flap: - Acellular dermal matrix graft - Guided tissue regeneration Footer Page of 161 Header Page of 161 RESEARCHES ABOUT SUBEPITHELIAL CONNECTIVE TISSUE GRAFT: In 2008, Ahathya RS et al did a study in India, at months post surgery, the result was 87.5% of denuded tooth root surface recovered [27] In 2008, Sergio L.S et al performed a clinical trial following-up of two Brazillian groups: the non-smoking group had better result than the smoking group [28] Also in Brazil by the year 2006, Carvalho performed surgery and followed-up months, the effectiveness of recovering the exposed tooth root surface was 96.7% [29] Harris et al in U.S in 2007 after months of postoperative follow-up showed the result that 95.4% of denuded root surface was covered [30] In 2002 he also performed the surgery on single denuded roots and multiple denuded roots and found that the sing tooth root surface was covered much more (90,3 % and 77%, respectively)[31] In 2007 Dembowska E et al did a research in Poland and followed-up 12 months, the result was 72.2% of exposed root surfaces recovered [34] Rossberg M et al studied a research on 39 teeth in Germany, he got the result of covering 89.7% of root surfaces after years [32] In Tehran, Sadat Mansouri S et al in 2010 studied 18 teeth with receded gum grading I and II, months later he achieved 85.7% of exposed root surfaces recovered [33] Cardaropoli 2011 tracked 12 months after surgery and showed the results 96% of toot root coverage [34] Nguyen Phu Thang's research in 2011 in Hanoi: 11 cases transplanted autogenous connective tissue to cover the tooth root surface, after months there were tooth roots were recovered partly [35] Chapter 2: SUBJECTS AND METHODS 2.1 Subjects of study Footer Page of 161 Header Page of 161 The study was performed on patients with tooth or group of teeth with gum recession examined at the Hanoi University of Medicine and Dental Center 225 Truong Chinh with the selection and exclusion criteria below 2.1.1 Selection criteria: Gingival recession grade I, II and III according to the classification of Miller [16] and there is no acute or chronic periodontitis 2.1.2 Exclusion criteria: Exclusion of patients with of the following criteria: Having the acute systemic illness or unstable chronic diseases such as diabetes, heart disease Pregnant women at the first months and the last months Smoking patients Denuded teeth are loosen Donor region (palatal mucosa from the first premolar to the first molar) has no sufficient thickness at least 2.5 mm (when the patient agrees to the surgery, before the start of the incisions, anesthesia the soft tissue at premolar palatal side and estimate the depth of the needle) Other diseases, such as inflammation of the mouth, tumors, cysts that interfere the surgery A history of allergy to anesthetics and antibiotics 2.2 Time and place of study: From March 2009 to December 2012 Study sites are OdontoStomatology Department (before November 2009), Medical University Hospital and Dental Center 225 Truong Chinh 2.3 Research methodology: 2.3.1 Study design and sampling: Footer Page of 161 Header Page 10 of 161 The uncontrolled open clinical intervention research to evaluate the effectiveness of the before-after model The patient had a tooth or group of teeth had agreed to have had gingival surgery was included in the study by convenient sampling, monitoring results, comparing before and after treatment 2.3.2 Sample size: The research is on the patients, but the evaluation of the results of the surgery is on the teeth (actually the patients had or gingival recession teeth and the gingival recession grades were different and results of recovering tooth surfaces on the same patient might vary), we calculate the sample size by teeth The number of surgery teeth was calculated using the formula [61]:   (  )  (  ) p p Z Z p  p N   / o o  /    p p a a a o We preferred α = 5% Power samples 1-β = 80% po = 92% according to research by Yong-Moo Lee et al [62] pa: re-covering ratio of the root surfaces estimated in this study (approximately 80%) N is equal to 43 In our study 49 gingival recession teeth were operated 2.4 The research steps: 2.4.1 Gather information before surgery: according to study design form Administrative information The reason to visit doctor Examine oral hygiene: based on OHI-S index (CI-S indices and DI-S indices) of Green and Vermillion in 1964 [63] 2.4.2 Steps to conduct research and gather information in surgery: Footer Page 10 of 161 Header Page 12 of 161 10 the root surface - Donor site: The soft palate mucosa from the distal of the canine to the distal of the first molar Antisepsis and anesthesia the mucosa at a distance about 5-7 mm from the gingiva border The first incision parallel to the border of the gingival margin - Add or more incision that perpendicular to the first incision at the both ends of the first incision Connective tissue is dissected from the mucosa with pouch opening style The connective tissue layer and the overlay mucosa are about 1.5 to mm thick If the mucosa is not thick enough, peel off the bone membrane, piece of connective tissue is removed and washed with saline and then soaked in physiological saline - The mucosa is sewn with polypropylene 5.0 or Vicryl 5.0 The recipient site is prepared to receive the connective tissue: - Removing granulation tissue, clean and smooth the root surface by grinding the root surface with smooth burs Root surface is exposed flat and at horizontal plane to alveolar bone Exposed root surfaces are highlighted with saturated citric acid for minutes then rinse with saline - Calculate the time of soaking the connective tissue in the saline water -The connective tissue graft is placed on the receiving surface in any direction, the edge of the connective tissue graft should leap over the margin of the exposed root surface about to mm, at the cervical portion the connective tissue graft should leap on the enamel margin Sew connective tissue graft that around tooth neck with prolene 6.0 - Reposition the flap over the connective tissue graft and sew the flap with interrupted and hanging suture It is not needed to cover the graft completely During the healing process, the epithelial cell with lap over the connective tissue, this is different from the method using the membrane Footer Page 12 of 161 Header Page 13 of 161 11 - Pressed saline gauze to surgical areas for about minutes to avoid dead space between the flap and the connective tissue graft, the dead space between the graft and the recipient surface Put the periodontal cement on the surgical wound *Gather information during surgery: the thickness of the palatal mucosa corresponding to the teeth 4, 5, 6; the time of soaking the connective tissue in the saline solution, enveloped flap or releasing incision flap *Guide to care for patients after surgery: On the first day, to avoid the risk of bleeding in the mouth, the patient should eat soft food, if the surgical site bleeds, take moist tea bag and place on the bleeding site and bite, then go to see a dental surgeon immediately To avoid possible gingival flap and connective tissue graft slipped, eat soft food and don’t chew hard for the first week, not brush teeth in the surgical area during the first two weeks, just clean gently with a cotton swab and betadine solution and saline via syringe, from the rd week, brush teeth gently with a soft brush, brush from the gingiva to the teeth *Postoperative: Patients have checked the next day, week later, periodontal dressing replaced at the 7th day, periodontal dressing taken off at the 12 th day, suture cut and removed at the 12th day Post-surgery drugs: Rodogyl (Spiramycine 750000UI combination with Metronidazole 125mg) dose of to tablets / days depending on patient weight Efferalgan 500mg * times the first days after surgery Alpha chymotrypsin 21μkatal edema, drink tablets * times per day the first week 2.4.3 Collecting information after surgery: - Is there any symptoms of bleeding and infection at the first week after surgery? Footer Page 13 of 161 12 Header Page 14 of 161 - Evaluate the results at the first week, 3, and 12 months postsurgery * After the first week: At the recipient site: after removal of periodontal dressing, observe the color of the soft tissue If it is red, it is not covered by the epithelial layer If there is spotted white color, it is epithelial cells If the soft tissue is necrosis, it will turn pale Don’t assess the inflammation at this time because in the healing phase there is inflammatory response If there is pus, it is considered less effective Evaluation Criteria at the first week are shown in Table 1: Criteria Highly effective group % of re-covering ≥ 80% Fairly effective group